Downhole actuator for well tools



Dec. 3, 1963 v. D. HANES DOWNHOLE ACTUATOR FOR WELL TOOLS 2 Sheets-Sheet 1 Filed April 20. 1959 m m m m VAUHAN DEAN HANES BY3 {ATTORNEY I g Dec. 3, 1963 v. D. HANES DOWNHOLE ACTUATOR FOR WELL TOOLS INVENTOR. VAUGHAN DEAN HANES I ATTORNEY g United States Patent Filed Apr. 20, 1959, Ser. No. $07,670 6 Claims. (Cl. 200-6153) This invention relates to firing devices adapted to initiate operation of tools suspended in a well and provided with self-contained operating means which require to be started by an external agency. The invention is specifically intended as a firing device for actuation of tools used in the oil well art.

Such wells require that a variety of operations be carried out such as acidizing, casing perforation, sealing off, or cementing. In such operations, actuation of the tool has to be effective at a particular point in the Well bore, often at a depth of some thousands of feet.

In most cases the firing device will be combined with a specialized tool, and since the particular construction of tool to be operated is immaterial to the invention, the following description will refer to the firing device only, used with a propellant operated tool, by way of example.

The lowering of a tool into an oil well, particularly those of considerable age or depth which are the type most frequently requiring special work, is often not a straight-forward matter. Such wells may not be truly vertical, casings may have lengths which have bulged, or there may be deposits on the inner surface of the casing or other obstructions that interfere with lowering of cable carried tools.

It will be evident that it is an advantage to use a wire or cable suspended tool capable of being jerked upward repeatedly in order to ease or work the tool past obstructions in the well.

In addition, even in Wells that are clean and straight there may be magnetic attraction between the well casing and the iron go-devil or cable that makes the use of a go-devil impractical, or there may be twists or kinks in the cable which prevent the downward free fall of the go-devil.

For reasons above given, it is impracticable to trigger the firing mechanism of a tool of the type described by the use of a conventional go-devil, which is a weight that is designed to be dropped down the well guided by the tool cable to operate trigger mechanism of the tool.

It is also much cheaper to provide oil well tools with self-contained firing means that may be operated by the well crew using the ordinary well equipment since it is expensive to employ specially trained men to furnish and operate the special electrical equipment required for electrically operated tools controlled from the surface.

It is a particular object of the invention to provide a firing device for tools operated by the pressure of gas generated by a charge of slow burning propellant or other source of potential energy, contained in the tool, the device being provided with electrical means to commence operation of the operating means of the well tool. The electrical means are preferably so arranged that the energization of the firing circuit is delayed until after several sharp upward movements of the device have been effected by the cable on which it is suspended.

It is another object to provide a firing device for oil well tools of the kind described, which is operated by an upward pull on the tool provided that said upward movement is effected at a relatively rapid rate, whereas a slow raising of the suspending cable is effective to lift the device without causing its actuation.

Another object of the invention is to provide a delay device in the firing mechanism of the device which will afford a definite delay period after the thing mechanism 3,113,188 Patented Dec. 3, 1963 'ice has been set into operation, during which period the tool can be accurately located by manipulation of the line suspending it to correct for possible minor loss of position due to the repeated raising and lowering of the device and attached tool that might have been effected to work the tool past obstructions in the well bore.

It is a further object of the invention to provide a simple and inexpensive device which may be used in most cases with the usual measuring line and reel used in the oil well industry and can be operated by maintenance men or other semi-skilled workers, thus avoiding the cost of special equipment and skilled crews.

It may be mentioned that a measuring line is a light line carrying a weight and running over a reel of known circumference, by way of example, three feet furnished with a counter by which the length of line payed out is read. Such line and reel equipment is standard commercial equipment, the lines coming in various thicknesses according to the purpose for which it is to be used. A line .187" designed to carry loads in excess of L250 lbs. isamply strong for use with the device of this invention.

With the above and other objects and features of the invention in view which will appear from the following specification and accompanying illustrative drawings, the invention comprises a case containing firing mechanism, a member contained in said case, and resilient means acting between the case and the contained member. One of the members is connected to the line suspending the device and tool in the Well, and the other member is connected to the tool, the relative axial movement of the case and contained member caused by jerks on the line being effective to operate the firing mechanism. Delay means are incorporated in the firing mechanism enabling the device and well tool connected thereto to be repeatedly jerked upwardly and lowered to work them past obstructions in the well before the firing mechanism is effective to set the operating means of the tool into action.

The invention particularly comprises a device as set forth having the case connected to the well tool and the member contained therein formed as a tension member connected to the suspending line, elements positioned in an electrical circuit with an associated source of electrical power being positioned in the case and being controlled by a switch and a delay device, the switch being operated by the relative movement of the tension member and case due to the inertia of case and well tool on each upward jerk on the suspending line but no signal being transmitted to the operating means of the well tool until after the predetermined delay period has terminated.

In the drawings:

FIG. 1 is an elevational view of the firing device of this invention connected to a packer being lowered into a Well, the well casing being shown in section.

FIG. 2 is a view similar to FIG. 1 but showing the packer set in position and the firing device being raised out of the well.

FIG. 3 is a fragmentary longitudinal section drawn on a larger scale, through the upper portion of the firing device with the mechanism contained therein in the unoperated position of the parts located within the device.

FIG. 4 is a sectional view similar to FIG. 3 but showing the parts in the operated position.

FIG. 5 is a fragmentary longitudinal section showing the parts located in the lower portion of the device.

FIG. 6 is a diagram of the electrical firing elements and the associated circuits located in the lower portion of the device; and

F16 7 is a diagram similar to that of FIG. 6- but showing the electrical elements in the operated position.

Referring now to FIG. 1, the firing device or actuator comprises a case generally indicated by the numeral 10,

resiliently supported on an elongated tension member generally indicated at 11, to which the line 12 or cable is secured.

A supporting wheel 13 and line matically indicated positioned outsi the well casing 15.

An oil tool such as a packer 16 is suspended from the case 10 of the firing device and is shown in the running-in position in FIG. 1. FIG. 2 shows the apparatus in the set position, in which the packer '16 is engaged with the well casing 15.

While .the packer 16 is shown for illustrative purposes only, reference may be made to copending application Serial No. 673,339, filed July 22, 1957, now U.S. Patent 3029872, for a specific disclosure of the packer shown in FIGS. 1 and 2.

The firing device of the present invention may be used to cause operation of a large number of well tools and devices, the only necessary common feature of which is that the tools are provided with selfcontained operating means required to be set into operation by an outside agency, which is provided by this device. Some of such well tools such as the packer 16 shown are intended to be left in the well in set position, while others such as casing perforating guns may remain attached to the initiating device after operation for removal from the well. Refenring now to FIGS. 3 and and going downward in the views, the case comprises a guide chamber 17 for the upper end of a composite tension member 11 which 18 formed as a cylinder 18 fitting slidably in, and extending through, an axial end opening 19 of a narrowed upper end 2d of the guide chamber 17.

The cylindrical portion 18 of the tension member terminates in a flattened portion 21 at its upper end which is provided with an eye 22 to which the line 12 is secured. At its lower end the cylindrical portion 18 is fitted with a spacing disc 23 in sliding engagement with the inner surface of the narrowed upper end 26 of guide chamber 17. The edge of disc 23 is scalloped as indicated at 24- in FIG. 4 to prevent any appreciable resistance to axial movement of the tension member through well fluid which is allowed to enter the guide chamber 17 through openings 25 in the wall thereof. The purpose of the constructional arrangement described is to reduce friction caused by packings to a minimum, only one such packing around the tension member being utilized. No effort is therefore made to keep =well liquid out of the 'guide chamber 17.

Below the narrowed upper end 20' the guide chamber 17 is widened out to full width of the case 16, and comprises a union member 26- of sufficient thickness to carry a packing gland 30, said union member 26 being threaded around its upper edge for the co-axial attachment of the guide chamber 17.

The union member 26 is threaded around its lower edge for the coaxial attachment of the barrel 28 of the device.

The tension member 11 is continued downwardly from the upper cylindrical portion 13 as a rod 29 passing through an axial bore in the union member 26. The packing gland 3t and packing 31 compressed thereby are positioned in the union member 26 to provide a liquid tight seal around the rod 29.

The barrel 28 is constructed to provide an upper liquid containing cylinder 32 and a lower cylinder 33 (FIG. 5) containing electrical components of the device, the two parts being screwed together as indicated at 34.

The upper cylinder 32 is formed with an inwardly projecting flange 35 toward its lower end, and a movable cylinder member '36 is fitted to slide within said flange.

The open end of the cylinder 36 is faced downwardly and provided with an outwardly projecting flange 37 which is a free sliding fit with the inner surface of upper cylinder 32.

An axial hole is provided in the closed end of cylinder 36 through which extends a stem 33 formed integral with a disc or collar 39 resting on the upper surface of the reel 14 are diagrame the upper end of closed end of cylinder 36. Disc 39 is provided with a central upwardly extending boss 40.

Rod 29 extends into the upper cylinder 32 and is threaded into boss 46', extending upward from disc 39.

The alignment of the components of the tension member 11 so far described is such that when the cylinder member 36 is in its lowest position the disc 23 is near the open end of the guide chamber but is still within it.

A coil spring 41 strong enough to carry the weight of the firing device and the well tool suspended therefrom without material deflection is arranged between the lower surface of the abutment or union member 26 and the upper surface of disc 33, being located in position at its lower end by a sleeve 42 which is screwed or otherwise mounted on boss 40.

A second coil spring 420 is arranged around the outer surface of movable cylinder 36 between the underside of flange 35 and upper surface of flange 37, and resiliently urges cylinder 36 downwardly.

A piston disc 43 working in cylinder 36 is secured to the end of stem 38. Restricted openings 4-4 are provided through the wall of the cylinder 36 near its closed end, and return ports 44m are near its open end and above flange 37.

The lower end of the upper cylinder 32 is closed by a closure 45 extending across the upper end of the lower cylinder 33. Upper cylinder 32 is therefore completely closed by the union 26 and closure 45 and made liquid tight by use of the usual gaskets.

The upper cylinder 32 is loaded with a quantity of preferably electrically non-conductive liquid 46 which fills the lower part of cylinder 32 and the interior of the movable cylinder 36. A suitable liquid for this purpose is a mineral switch insulating oil or a synthetic insulating oil of the chlorinated hydrocarbon type, such insulating liquids are commercial products sold under various tradenames.

The purpose of the resiliently mounted movable cylinder 36 is .to provide for a dash-pot arrangement. Rather than provide tension member 11 with an extension to operate a plunger 49a: directly, the movable cylinder 36 is disposed therebetween to operate the plunger which, in turn, actuates a single pole-single throw switch 49. This arrangement afi'ords for switch 49 a cushioned operation in place of the hammering to which it would have been otherwise exposed.

The lower cylinder 33 is also rendered liquid tight to exclude well liquid by an end plug 47 (FIG. 5) screwed to the cylinder 33 as indicated at 48 and contains the electrical components of the device with the exception of a switch 49 positioned in the upper cylinder 32.

The lead from switch 49 into lower cylinder 33 is passed through an insulation member 50 mounted in and sealing a hole drilled through the closure 45. A lead connecting the output from the electrical means contained in the device to the well tool to be put into operation is led through an insulating and sealing member 51 mounted in a central bore 52 through end plug 47.

The components of the electrical circuit are shown diagrammatically in FIG. 6 in inoperative position and comprise the switch 49, which is of the normally closed type, that is, pressure is required on the plunger 49a of the switch to open the circuit controlled thereby. This pressure is applied by spring 42a (FIG. 4) in the normal position of the parts.

As shown in FIGS. 6 and 7, one contact of the single pole-single throw switch 49 is grounded by lead 53, while the other contact is connected by lead 54 to one terminal of a first battery 55. The other terminal of the battery 55 is connected by lead 56 through the solenoid of the stepper switch 57 to ground at 58. It is to be noted that stepper switches are arranged to move a switch arm a limited distance only, or one step, at each energization.

A second battery 59 is connected by one terminal and lead 60 to the live terminal 61 of the stepper switch 57, the moving arm 62 of which is grounded. In initial position arm 62 rests against the front of a stop 6;: while at the end of the travel of the arm it rests against the back of the stop.

The other terminal of battery 59 is connected by lead 64 to one terminal of the motor winding 65 of an electrically driven time delay device 66, the other winding terminal being grounded. The time delay device 66 may be of any suitable type capable of being put into operation by an electrical impulse such as one driven by clockwork and a wound spring, the clockwork being released for operation by a solenoid operated detent. It is to be understood that a motor driven time delay device is shown only by way of illustrative example. The moving arm 67 of the time delay is grounded and rests in unoperated position against a stop 68, and when the time has expired for which the device has been set, rests against an adjustable contact 69 which is connected by lead 70 to one terminal of a third battery 71. The other terminal of battery 71 is connected by lead 72 through an ignition element, such as the high resistance wire '73 of a squib (not shown) positioned in the well tool to be operated, to ground.

A squi is a small cartridge containing pyrotechnic material packed around a high resistance wire which when heated by the passage of an electric current ignites the pyrotechnic material which in turn ignites a charge of propellant located in the tool, generating gas pressure which operates the tool.

It is to be understood that well tools operated by other means than by the generation of gas by the burning of a charge of propellant may be actuated by the device of this invention. For example, the squib or other device operated by the flow of current from battery 71 might admit well fluid under static pressure to operate the tool, or to release compressed gas from a container. Many such well tools operated by self-contained operating means are well known in the art.

The tool may be suspended from the firing device of the invention by a shear coupling '74 (FIG. shown as a U-shaped element, the legs of which are passed through holes in the upper end of the suspended tool and lie in a groove 75 formed in the lower portion of end plug 47. The close liquid-tight connection between the firing device and the well tool shown in FIG. 5 is typical of the connection where a tool intended to be left in the well, the element 74 being sheared either by gas pressure developed in the tool, as in copending application Serial No. 673,339, now U.S. Patent 3,029,872, previously referred to, or bya hard pull on the cable. If the firing device is to be used with a tool which is raised after operation, or with an instrument which is to be raised out of the well, the connection shown in FIG. 5 may still be used since member 74 can be readily removed after the firing device has been raised, by the use of a pulling tool.

Operation When it is required to position a tool of the kind operated by means positioned within the tool and capable of furnishing the power required when actuated by electrical means, the tool is suspended from the device by a suitable coupling illustrated in the drawings as a shear The firing device will of course be fitted with the three batteries 55, 59 and '71 in working order and with the stepper switch 57 and time delay device 66 set back to zero. If there is no obstruction to the lowering of the tool to the depth required, lowering will be stopped and the cable raised sharply or jerked and then lowered to the approximate required depth for the number of times required to cause the stepper switch arm to rotate, one step for each jerk, to the live contact 61 and the device will then commence operation by the energization of the time delay device.

At each jerk of the cable which is attached to the tension member 11 the inertia of the casing and tool suspended therefrom results in the momentary compression of spring 41 and the upward movement of disc piston 43 in movable cylinder 36. Since cylinder 36 is full of liquid, the liquid above piston 43 can escape through the restricted openings 44, and therefore cylinder 36 is moved upwardly, compressing spring 42a and raising flange 37 from switch plunger 49a. A circuit is thereupon completed from battery through the stepper solenoid resulting in moving the arm 62 thereof forward by one step.

The liquid flowing through the restricted openings 44 flows into the liquid in the chamber 32. Liquid located in the space between the flanges 35 and 37 and surfaces of the cylinder and chamber is enabled to escape through ports 44a into the cylinder 36 below the piston disc 43 to prevent back pressure from this portion of the body of liquid. Hence the cable 12 may be regarded as a motion transmitter and the movement of the piston disc or push member 43 in the cylinder 36 may be regarded as a movement discriminating means, in that when the piston disc 43 is raised slowly in the cylinder, this move- ,ment is not transmitted to the cylinder, but when the piston disc is raised rapidly in the cylinder, the piston disc and the cylinder function as though they were momentarily connected together.

The purpose of the time delay device is to permit accurate positioning of the tool to be etfected since the repeated raising and lowering of the cable may have resulted in the tool hanging some distance above or below the exact point desired. The time delay may be set to operate, for example, ten minutes after the final jerk, which will give the hoist operator time to raise or lower the cable the few feet required to accurately position the tool before the timing device completes a circuit from battery '71 through the ignition device in the tool, causing the operation of the latter.

At the cessation of each upward pull and during the following lowering movement of the cable, spring 41 will return the case 10 to its original position relative to the tension member 11, and disc piston 43 will travel downwardly in the movable cylinder 36, the fluid reversing its direction of flow through restricted openings 44 and ports 44m and the spring 420 will again cause the flange 37 to engage with and depress the switch plunger 49a thus again interrupting the operative circuit.

It will be noted that the firing device of the invention is particularly designed to enable the device with its suspended tool to be repeatedly jerked to help work the tool past partial obstructions in the well. The operation of the device when subjected to repeated jerking upward and again lowering will obviously be the same as that described for an unobstructed lowering of the tool except that the number of upward jerks must not exceed the number of steps for which the stepper motor is arranged, minus the final jerk which sets the time delay device 66 into operation. For instance, if the stepper switch has eight steps and the tool cannot be positioned after seven upwand jerks, the tool must be Withdrawn from the well with a steady pull which will not be efiective to cause operation of the device. If the tool can be positioned after only five upward jerks, then three more jerks will have to be given the firing device, lowering it each time to its approximately correct position whereupon the time delay device will commence to operate, and finally positioning it during the period of grace afforded by the time delay device, before the tool is finally actuated into operation.

It is to be understood that while the firing device has been described with refernce to a well tool, the device may be used to position and set into operation various instruments used for taking readings in wells, the term tool is there-fore to be understood to include any instrumentalities used in wells and provided-with self-contained operating means requiring to be started by a separate device with which the instrumentality is more or less closely associated, and which is provided with means for generating an electrical impulse transmitted to said instrurnentality.

I claim:

1. An actuator for an oil well tool comprising: a case having a longitudinal cavity, liquid contained within said case, a cylinder closed at its upper end and open at its lower end moveably mounted in said case, a first resilient means positioned between said case and said cylinder urging the cylinder downwardly, a piston moveab'ly mounted in said cylinder, a connecting rod fixedly attached to said piston extending upwardly through a loose fitting aperture in the closed end of the cylinder, a collar, fixedly attached to said connecting rod, an abutment secured to said case, a second resilient means acting between said abutment and said collar to urge said collar into contact with said cylinder, a switch attached to said case, said switch having an operating member held in operational contact with said cylinder by the biasing force of said first resilient means exerted thereon, a cable fixedly attached to said connecting rod for exerting an upward force thereon whereby an upward force will be exerted on the piston in said cylinder tending to compress liquid in said cylinder between the piston and the base of the cylinder, restricted apertures in the cylinder to permit liquid confined between said piston and the base of said cylinder to escape therefrom when an upward force is exerted on said piston, wherebywhen a slow pull is exerted by said cable on said connecting rod and said piston the confined liquid in said cylinder can escape through said apertures fast enough so that movement of said piston in said cylinder is not transmitted to said cylinder, but a rapid upward movement of said connecting rod and said piston momentarily increases the pressure in the liquid confined in said cylinder faster than the pressure is being relieved by the passage of liquid through the restricted apertures in the cylinder so that the upward movement of said piston is transmitted to said cylinder whereby the cylinder is momentarily lifted out of contact with the actuating member of said switch and the switch is operated.

2. An actuator comprising: a case having a longitudinal cavity therein, liquid contained within said case cavity, a cup-shaped member received by the said case cavity and positioned with its open end down and its base up, first resilient means positioned between said case and said cup-shaped member, urging said cup-shaped member downwardly, rod means positioned longitudinally within said case cavity with a portion thereof freely penetrating an aperture in the base of said cup-shaped member, a collar on said trod means, an abutment secured to said case, a second resilient means positioned between said collar and said abutment urging said collar in contact with said cup-shaped member, a means for confining liquid in said cup-shaped member, said liquid confining means fixedly attached to said portion of said rod means penetrating the cup-shaped member whereby movement of said rod means causes a corresponding movement of said liquid confining means in said cup-shaped member, a device attached to said case, said device having an operating member associated with said cup-shaped member and normally held in operational contact therewith by the biasing force of said first resilient means, means attached to said rod means for exerting an upward force thereon, whereby an upward force will be exerted on the liquid confining means in said cup-shaped member raising said liquid confining means and tending to compress liquid between said liquid confining means and the base of the cup, restricted apertures in said cup-shaped member to permit liquid confined between said liquid confining means and said cup-shaped member to escape therefrom when an upward force is exerted on said liquid confining means whereby when a slow pull is exerted on said red means and said liquid confining means, the confined liquid in said cup-shaped member can escape through said apertures fast enough so that movement of said liquid confming means in said cup-shaped member is not transmitted to the cup-shaped member, but a rapid upward movement of said rod means and said confining means momentarily increases the pressure in the liquid confined in said cup-shaped member faster than the pressure is being relieved by the passage of liquid through the restricted apertures of the cup-shaped member so that the upward movement of said liquid confining means is transmitted to said cup-shaped member whereby the cupshaped member is momentarily lifted out of contact with the actuating member of said device so that the device is operated.

3. The device described in claim 2 and in addition an inwardly extending guide member inside and fixedly attached to the case, surrounding and in spaced relationship with the cup-shaped member for guiding said cupshaped member in said case.

4. The device described in claim 2 and having in a liquid-tight partition fixedly attached to the case transversely positioned across the case and surrounding the rod above the cup-shaped member and below the cable, and a second liquid-tight partition fixedly attached and transversely positioned across the case and below the said switch for confining said liquid therebetween.

5. An actuator for an oil well tool as defined in claim 1 and having an outwardly extending peripheral guide flange fixedly attached to said cylinder and positioned adjacent and in spaced relationship to the case, and an inwardly extending guide flange attached to the case in spaced relationship with the said cylinder whereby the movement of the cylinder is guided and centered on the case, said first resilient means acting between said inwardly extending flange and said outwardly extending flange to bias the cylinder downwardly against the operating member of the switch.

6. An actuator for an oil well tool as defined in claim 1 having a liquid-tight partition transversely positioned across the said case positioned above the said cylinder and below the said cable to confine the liquid therebetween, said shaft passing through said liquid-tight partition.

References Qited in the tile of this patent UNITED STATES PATENTS 2,331,058 Stick Oct. 5, 1943 2,640,547 Baker et a1. June 2, 1953 2,870,841 Conrad et a1. Jan. 27, 1959 2,871,946 Bigelow Feb. 3, 1959 

1. AN ACTUATOR FOR AN OIL WELL TOOL COMPRISING: A CASE HAVING A LONGITUDINAL CAVITY, LIQUID CONTAINED WITHIN SAID CASE, A CYLINDER CLOSED AT ITS UPPER END AND OPEN AT ITS LOWER END MOVEABLY MOUNTED IN SAID CASE, A FIRST RESILIENT MEANS POSITIONED BETWEEN SAID CASE AND SAID CYLINDER URGING THE CYLINDER DOWNWARDLY, A PISTON MOVEABLY MOUNTED IN SAID CYLINDER, A CONNECTING ROD FIXEDLY ATTACHED TO SAID PISTON EXTENDING UPWARDLY THROUGH A LOOSE FITTING APERTURE IN THE CLOSED END OF THE CYLINDER, A COLLAR, FIXEDLY ATTACHED TO SAID CONNECTING ROD, AN ABUTMENT SECURED TO SAID CASE, A SECOND RESILIENT MEANS ACTING BETWEEN SAID ABUTMENT AND SAID COLLAR TO URGE SAID COLLAR INTO CONTACT WITH SAID CYLINDER, A SWITCH ATTACHED TO SAID CASE, SAID SWITCH HAVING AN OPERATING MEMBER HELD IN OPERATIONAL CONTACT WITH SAID CYLINDER BY THE BIASING FORCE OF SAID FIRST RESILIENT MEANS EXERTED THEREON, A CABLE FIXEDLY ATTACHED TO SAID CONNECTING ROD FOR EXERTING AN UPWARD FORCE THEREON WHEREBY AN UPWARD FORCE WILL BE EXERTED ON THE PISTON IN SAID CYLINDER TENDING TO COMPRESS LIQUID IN SAID CYLINDER BETWEEN THE PISTON AND THE BASE OF THE 